関連ワード:
what is eras in geologic time scale what is periods in geologic time scale what is the oldest era in geologic time scale what is the longest era in geologic time scale the current era in the geologic time scale is the what are the 3 eras in geologic time scale what are the four eras of the geologic time scale what era in the geologic time scale lasted the longest what era in the geological time scale was known for the age of the reptiles what are different eras in the geologic time scale
